GMO Internet Admits Security Flaw Went Unfixed for Over Two Years Before Cyberattack

GMO Internet Group Inc. did not fully address a security vulnerability despite being warned about the weakness in 2024, before a recent cyberattack led to a data breach, CEO Masatoshi Kumagai said on Monday.

According to Kumagai, the company received warning information about the vulnerability early on but had not taken thorough remedial measures. The flaw was later exploited in the cyberattack that resulted in the data leak.

The incident raises questions about the company's process for handling security alerts, given that more than two years passed between the discovery of the weakness and the incident.

There is currently no detailed information on the scale of the affected data or the next steps GMO Internet Group will take.